First paragraph (this article has no abstract)

In human genetics, the equivalent of finding gold mine is finding a genetically isolated
population with excellent medical records. Inbreeding often magnifies the effects
of single gene traits because homozygosity is more common, and a society in which
family medical histories can be traced back for many generations allows patterns of
inheritance to be ascertained with confidence. Given the mobility of the human population
today, such societies have become rare, but they do exist. There was a lot of excitement
in the early 1990s about genetic studies of Mormon communities in Utah in the USA,
and they have provided useful information. So have French Canadian communities in
eastern Canada and some groups in rural India. But the society that attracted the
most attention - and the program that has created the most controversy - is that of
Iceland.